Research of Physical and Mechanical Indicators of a Plate Made on the Basis of Rubber Crumb, Ethylene Propylene Membrane Granules and Polyurethane Glue

The article describes the study of the possibility of using a plate made of rubber crumb, ethylene propylene diene membrane (EPDM) granules and polyurethane adhesive for the construction of subway structures. The key properties of this combination of plate components have been determined with regard to the possibility of using it in underground infrastructures, in particular in tunnels exposed to mechanical loads and moisture. An important aspect is the study of the mechanical and physical characteristics of the material of the plate made of rubber crumb, EPDM granules and polyurethane adhesive. The technology of manufacturing the plate allows providing the material with elasticity and deformability, as well as effective vibration absorption and noise reduction, which are critical requirements for underground facilities. Polyurethane adhesive, used as a bonding element, provides adhesion to coarse aggregate particles (rubber crumb and EPDM granules) and resistance to mechanical damage, which is especially important for structures subjected to loads in underground conditions. The article also provides studies of the physical and mechanical properties of this composite material, such as compressive strength, tensile strength, deformation modulus and Poisson's ratio, as well as its reaction to the action of water and alkaline media. During the tests, it was observed that the "HUMINAT" plate is a deformable elastic heterogeneous material that is able to change its shape and dimensions when compressed, and after removing the load after 2-3 s restores its initial parameters. This indicates the presence of relaxation properties of the material. This property is especially pronounced during compression, when the material can exhibit significant deformation, which decreases after removing the load. In turn, during stretching, relaxation is much less pronounced. During tensile tests, the material breaks down quite quickly, since the tensile strength of the material is mainly determined by the adhesion forces of the adhesive to the surface of the rubber crumb and EPDM granules. It is noted that only the mechanical component of adhesion acts between the components of the “HUMINAT” plate, and there is no chemical adhesion. The interaction between the components is not due to diffusion or electrostatic forces, but only to the mechanical adhesion of the elements. This affects the overall mechanical behavior of the material, in particular its stability during cyclic loads. In general, the “HUMINAT” plate can be a promising material for use in subway construction, since the plate material is elastic, deformable and prone to relaxation, and also withstands moderate mechanical loads. However, its use should be limited to conditions where moisture is not a critical factor. The manufacturing technology and characteristics of the material allow achieving economic benefits while maintaining the necessary functionality for underground infrastructures.